19
CONDITION #2 continued.........
C. IF FAN PRESSURE MEASURES “BELOW-NORMAL” CONDITIONS:
• LESS THAN 1.45" W.C. ON AM-100 & -150
• LESS THAN 1.0" W.C. ON AM-300
POSSIBLE CAUSE
VERIFICATION
SOLUTION
Air Inlet Pipes/Fan Assembly
Turn “OFF” Rocker Switch. Turn gas
If fan pressure increases to normal
(AM-100 & -150 Only)
valve top knob OFF. Remove lid
range, check the inlet piping, inlet
from ACC. Turn Rocker Switch “ON”
muffler & inlet vent terminal for
and hold fan assembly firmly in place
obstruction.
in its typical mounting position.
Observe fan pressure (see
If fan pressure remains the same,
“Procedures” section -
repair or replace fan assembly. If
“FAN PRESSURE.”)
ok - proceed with check.
Obstructed
Turn Rocker Switch and Gas Valve
If loose, secure blower wheel
or Loose Blower Wheel
top knob OFF. Remove Air Cushion
properly on shaft. Remove
(AM-300)
Chamber cover. Remove fan from
obstructions. If ok proceed with
mounting studs & check blower
check.
wheel is secure on shaft,not rubbing
against housing & free from
obstruction.
Fan Assembly
Hold fan assembly in typical
If motor runs ok - check for inlet vent
(AM-300)
mounting position & turn Rocker
restriction including inlet air orifice
Switch ON (gas OFF). Observe fan
located in inlet adapter on AM-300.
operation and direction of rotation.
See FIG.7.
(DO NOT LUBRICATE MOTOR).
If motor runs slowly, replace
assembly.
Fan Inlet Gasket
Check for compression marks on
If gasket is not sealed properly,
(AM-100 & -150 only)
gasket for complete seal to air inlet
replace it. See “Procedure”
adapter & that gasket seals
section in this manual for details.
completely (360-degrees) around
fan inlet opening.
CONDITION 3 - BOILER IS SHORT-CYCLING
Boiler ignition occurs, strong start but runs only short time (red and green lights on) and then suddenly stops. If
lights are operational, observe lights as detailed below and follow appropriate procedures.
• IF BOTH RED & GREEN LIGHTS GO OUT WHEN BOILER STOPS, BOILER IS RESPONDING TO AN
OPERATIONAL CONTROL THAT IS SATISFIED. CHECK SET POINTS ON HI-LIMIT, CIRCULATOR,
THERMOSTAT AND OTHER BOILER CONTROLS. ADJUST AS NECESSARY.
• IF GREEN LIGHT GOES OFF WITHIN SECONDS AFTER BOILER STOPS; RED LIGHT STAYS ON;
AND BOILER DOES NOT RESTART. PROCEED WITH (3B) CHECK BELOW.
• IF GREEN LIGHT GOES OFF WITHIN SECONDS AFTER BOILER STOPS; RED LIGHT STAYS ON;
BUT BOILER IMMEDIATELY RESTARTS, PROBLEM IS COMBUSTION RELATED. PROCEED WITH
OPERATIONAL CHECK BELOW (3A).
